Joint AP coverage adjustment and user association optimization for load balancing in multi-rate WLANs

We investigate the problem of joint AP coverage adjustment and user association optimization for load balancing in multi-rate WLANs in this paper. We first divide the problem into two sub-problems and then formulate them as mixed integer linear programming models, which aim to minimize the AP utilization of the most congested AP while satisfying users' traffic demands. Then we design two corresponding heuristic algorithms that are performed in sequence to address the problem. Finally, we conduct extensive simulations to evaluate the performance of the proposed algorithms. The results not only show that the algorithms can balance the loads among APs effectively and efficiently, but also demonstrate that the solutions of joint AP coverage adjustment and user association optimization outperform that of AP coverage adjustment with low overhead.